Office-based messaging systems are currently in use in which a message can be sent to a specific group of recipients in a company to whom the message has relevance. A group can be defined by an individual for personal use, at a system level for use by all users, or at an intermediate level, such as for use within an organizational department. The sender need only specify the group name in the message “To:” field, and the messaging system will resolve the group name into the list of individual recipients that comprise the group, and the message will be sent to the group members. In addition, certain messaging systems allow the message sender to specify a message expiration. For example, Microsoft Office Outlook allows a message sender to specify an “Expires After:” date and time. Microsoft and Outlook are registered trademarks of Microsoft Corporation. A message in an Outlook recipient's inbox that has “expired” will appear, for example, with a red line through the message on the next screen refresh after the expiration time. A batch process might run once a day that will move expired messages from recipients' inboxes to their “deleted” folders.
It is also known to route messages based on “presence” information. For example, U.S. Patent Publication 2007/0299927 to Knauerhase describes a system that maintains a user profile that includes preference by priority as to which “channels” the user wishes to receive messages, and also accessibility states as to those channels. Channels might include email, landline and cell phones, instant messaging accounts, PDA's, etc. For example, a user's preferences may be defined such that messages are received first by email, and then by cell phone. If the user is unavailable via email, then messages will be routed to the user's cell phone. A store-and-forward system, such as email, can be used as a fall-back if a user is unavailable by any of the channels the user has specified.